This invention relates generally to the field of mattresses, and in particular to so called one-sided or no-flip mattresses. More specifically, the invention in one embodiment relates to such mattresses that are constructed using an inner core of springs although other cores may be used as well.
Spring mattresses have been in use for over 100 years. Existing spring mattresses use a variety of spring types to form their inner core. Perhaps the most common is the traditional wire spring assembly having a set of interconnected wire spring coils. As is well known in the art, a major supplier of such springs is Leggett & Platt.
Another type of spring assembly is the so-called Marshall construction that was developed in the late 1890's by Marshall Mattress of Toronto, Canada. The Marshall design utilizes fabric pockets to encapsulate each spring. In this way, the coils may flex separately from each other. Examples of such pocket coil spring designs are described in, for example, U.S. Pat. Nos. 685,160; 4,234,983; 4,854,023; 6,029,957; and 6,295,676 and published PCT No. WO99/32396, among others. The complete disclosures of all these references are herein incorporated by reference.
Traditional mattresses have a padding layer disposed both on top of and beneath the core of springs. This is encased within a fabric or ticking, and may optionally include additional layers of padding to form a “pillow top” mattress as is known in the art. Because of potential uneven wear during the life of the mattress, many manufacturers recommend periodically rotating or flipping the mattress. However, because this can be difficult and inconvenient, many users do not follow this practice. For those that do, this exercise can be annoying.
As a result, the one-sided or no-flip mattress has been developed. Several manufacturers have developed and sold such mattresses at least as early as the mid 1990s. For instance, Sleep Therapy mattresses have been sold by Wickline Bedding Co., San Diego, Calif. since the early 1990s. These mattresses have a polyurethane foam layer underneath the springs and a traditional padding layer on top. This design was subsequently adopted by Simmons Company as demonstrated by their U.S. Pat. No. 6,243,900, the complete disclosure of which is herein incorporated by reference.
This invention is related to improved methods for manufacturing so called one-sided or no-flip mattresses. As described hereinafter, such mattresses provide increased firmness, stability and comfort, among other features. Further, such mattresses may be economically produced to provide a commercially attractive mattress.